115 OMC Turbojet...Why does it overheat????

[klawunf]

I have a 1994 Four Winns Fling with a 115 hp OMC Turbojet. It runs fine at cruising speed. It overheats at low speed or idle. I have flushed it and varified good water flow. I installed new thermostats. Have you solved this problem????

 

[drackley]

Re: 115 OMC Turbojet...Why does it overheat????

I have the same engine, and my research has revealed the following. The engine was very had a problem with sand being sucked up and passed through the cooling system. The passages in the heads are small, and can clog. This is where the heat sensors are. They even offer a sand filter for this particular engine. If you have done the usual things, run the engine until the alarm goes off and unplug the sensor (brown wire from head) one at a time to determine which side overheated. I would then remove not the head, but the head cover and see if you have a restriction.

 

[klawunf]

Re: 115 OMC Turbojet...Why does it overheat????

Thanks. I will give it a shot.

 

[seahorse5]

Re: 115 OMC Turbojet...Why does it overheat????

It the idle is too slow, the motor will overheat as it gets its cooling water from the jet unit. Unlike an outboard, the Turbojet idles at 1200 rpm in the water, in neutral.